What was a flier from the outset in signing Shaun Rogers already is looking like a failed — and expensive — experiment by the Giants.

A surprise signing by Big Blue in April, the veteran defensive tackle didn’t do much of anything during the offseason program that wrapped up last week except cost them promising young tight end Jake Ballard.

With Rogers unable to participate due to a mysterious elbow condition that neither he nor the Giants will talk much about, general manager Jerry Reese exposed Ballard to waivers for roster purposes so he could bring back reserve defensive tackle Rocky Bernard.

The move backfired when Ballard was claimed by the Patriots, leaving the Giants with no Ballard, an injured Rogers and a marginal player in Bernard at what already was by far the deepest area on the team.

The whole situation also had the famously grouchy Rogers in anything but a good mood when reporters dared to even stop by his locker during the Giants’ recently concluded mini-camp.

“I would like to think I’m the expert about myself, but that’s not usually how y’all [reporters] write it,” the former Lion, Brown and Saint said in response to an innocuous question about his general health. “Y’all [reporters] are pretty much all the same.”

The Giants’ decision to sign the 33-year-old Rogers was curious from the outset. Although he played in all 16 games for the Saints last season, he managed just 14 tackles and wasn’t re-signed even though New Orleans knew its defense was probably going to be decimated by free agency and the NFL’s bounty penalties.

Even Rogers admitted when the Giants inked the former first-round pick and three-time Pro Bowl selection that he was halfway expecting to be forced into retirement, although Rogers claimed last week that there were other teams interested this offseason.

The Giants appeared to signal a desire to get bigger and bulkier in their defensive interior with the addition of the 6-foot-4, 340-pound Rogers, who had been a Casey Hampton-style nose tackle in Cleveland.

But with Rogers unable to do anything more than study the Giants’ playbook, the combination of the elbow and the surprise re-signing of Bernard are leading Big Blue watchers to wonder if Rogers will ever play a snap for the reigning Super Bowl champions.

“He is in the classroom,” Tom Coughlin said when asked about Rogers recently before quickly changing the subject.

Rogers isn’t exactly making any guarantees when asked if he expects to be available for the start of training camp in Albany next month. The lack of vigor in his voice indicates Rogers himself wouldn’t be surprised if the Giants decided to end their relationship soon.

“That’s up to them to decide,” Rogers said. “I feel like I can play football at any point in time. What my role is will be determined by the coaches and how they feel.”